TCP/UDP/IP data transport over hybrid fiber coaxial cable (HFC) networks for Internet or enterprise service requires new approaches for scaling, provisioning, authentication, service differentiation and quality of service. MAC layer bridging alone at the head end will fail to provide scaling, conditional access, and quality of service. Additionally, the half duplex, shared nature of the HFC network and the need for multiple return paths per forward path, will encourage the use of packet layer routing in the head end. Data/cable industry suppliers have been concentrating on physical and link layer issues such as modulation, forward error correction and media access control (MAC) protocols. Less thought has been given to system software issues which are crucial to scaling residential broadband networks. By scaling, we mean the capability to provision, diagnose, manage and ensure expected performance when thousands or millions of subscribers are attached. This paper describes some software scaling issues and discusses cable DHCP and virtual dialup as examples of software scaling solutions.